For decades, the origin of helium enrichment in O-type stars has remained an open question. We investigate the correlation between surface helium abundance (Y He) and orbital parameters for a sample of 45 O-type SB1 systems, including Cyg X-1. We find seven He-rich systems, all of which are concentrated at short orbital periods (P ≲ 15 days) and

In recent decades, large panoramic surveys have discovered a number of extremely faint and compact Galactic satellites, known as ultra faint compact satellites (UFCS). The nature of these stellar systems is uncertain, both because they occupy a region of the M V - R h plane where dwarf galaxies and star clusters overlap, and because of the

Context. The architecture of our Solar System, with inner small planets (ISPs) and outer giants, may or may not be common. Understanding whether a correlation exists between ISPs and outer cold giants is key to evaluating how common systems with a similar architecture to our own are. Aims. This study aims to build a large, homogeneous sample of

The present-day architecture of planetary systems contains information about their formation and migration histories. The origin of hot Jupiters (HJs; P ≲ 10 d, R p > 8 R ⊕) has long been a matter of debate. While most of them are found to be `lonely', there is a rare population of HJs hosting small inner-orbit companions (eight known as of May

Galaxy formation models predict that galaxies grow inside-out, becoming larger over time. While observations broadly support this paradigm, the nature and timescales of this growth remain poorly constrained. We report the discovery of an extremely faint and young (~600 Myr) stellar component in the outer regions of the nearby galaxy Messier 74 (M74

Galaxy mergers are expected to strongly reshape the internal properties of galaxies. However, their impact on chemical enrichment and star formation at different galactocentric radii remains poorly understood. In this study, we investigate how the merger process affects the radial distribution of gas-phase metallicity (oxygen abundance, O/H) and